1. Field of the Invention
The present invention relates to a cam follower lever used in a cam weave mechanism and to a method of manufacturing such a lever. The invention also relates to a cam weave mechanism comprising such a lever and a loom fitted with such a mechanism.
2. Brief Description of the Related Art
In the field of looms, cam weave mechanisms are known that comprise a series of oscillating levers in numbers equal to those of the heddle frames to be mounted on the looms, each oscillating lever being designed to be coupled to one of the frames and fitted with two rollers which interact with two tracks of a complementary cam rotated by a common shaft. The twin tracks of one and the same cam are offset axially and the rollers supported by the associated lever must have the same axial offset as the tracks of the cam.
To do this, it is known practice, for example from EP-A-0 225 266, to mount the rollers of a lever protruding either side of a core. This generates twisting or overhanging moments on the shafts that support the rollers, which induces flexings, mechanism fatigues, even breakages of these elements and a loss of precision during operation. EP-A-0 225 266 also proposes to mount the rollers of a lever in grooves machined in solid cores that are relatively thick. Such a technique is extremely costly, particularly because the core of the lever is relatively voluminous.
Furthermore, it is a known practice from FR-A-2 317 395 to produce a lever formed essentially of two flanges provided with steps. It is also known from FR-A-2 259 173 to mount the rollers of a lever in a yoke between two pairs of flanges that are cambered and mounted in opposition. The steps and cambers of the main portions of the flanges of the known levers are supposed to make it possible to compensate for the offset between the rollers and the mid-plane of the lever. In practice, they are subjected to flexing forces that are too high for the metal sheets forming them, which causes them to deform and even break.